<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
     <form action="roleAction" method="post">
         用户名:<input type="text" name="user.username"><br/>
         密码:<input type="password" name="user.password"><br/>
         角色:<input type="text" name="user.role.roleName">
         <input type="submit" value="提交">
     </form>
</body>
</html>